Mandrel

ABSTRACT

A method and apparatus for locating a barrier panel within a soil formation. The apparatus comprises a mandrel plate at least one leading blade located proximate to the bottom end of the mandrel plate. The apparatus further comprises at least one retainer plate pivotally supported from the mandrel plate between the bottom end of the mandrel plate and the leading blade. The retainer plate is rotatable between an engaged position to retain a barrier panel proximate to the front surface of the mandrel plate and a disengaged position. The method comprises locating a barrier panel against the mandrel plate, displacing the leading blade from a position distal to the mandrel to a position adjacent to the mandrel so as rotate the retainer plate from a disengaged to an engaged position capturing a bottom edge of the barrier panel and pressing the mandrel plate and barrier panel into the soil formation.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to forming ground barriers in general and in particular to a method and apparatus for inserting a ground barrier panel into a soil formation.

2. Description of Related Art

In the field of geotechnical engineering, it is frequently necessary to physically isolate one area in a soil formation from an adjacent area for a variety of purposes. These purposes may include providing either a temporary or a permanent retaining wall, or may be for the purpose of isolating contaminants in one of those areas of soil from the other. One known method of providing such isolation is to insert successive panels into the soil formation between the two areas so as to form a continuous barrier therebetween. In the case of remediation work where the purpose is to contain and remove contaminants from the soil of one of the areas, it is frequently necessary to ensure that the barrier created by such panels does not have significant gaps therebetween which may allow the contaminants to escape.

One common method of inserting such panels into the ground is to vertically orient the panel above the surface of the soil formation and apply sufficient pressure to the top of the panel so as to forcibly insert the panel into the soil formation. Successive panels may be thereafter similarly inserted into the soil formation with a slidable interconnection between the two adjacent panels to assure continuity. Conventionally a mandrel formed of a plate of metal having a cross section corresponding to the panel is utilized to support the panel during the insertion process.

Previous methods of supporting the panel during insertion have not been satisfactory. In particular, Applicant is aware of U.S. Pat. No. 5,803,672 to Glass et al. including hinged flaps located proximate to a bottom end thereof which are operable to rotate into an upward orientation thereby protecting the bottom edge of a panel located against the apparatus.

However, as the flaps in the apparatus of Glass et al. are hinged from a single side of the mandrel, they may be prone to directing the bottom edge of the mandrel in one direction due to the angled surface the flaps present. Accordingly, the apparatus of Glass et al. may impair the ability of the panels to be inserted in a straight or vertical orientation.

SUMMARY OF THE INVENTION

According to a first embodiment of the present invention there is disclosed an apparatus for locating a barrier panel within a soil formation. The apparatus comprises a mandrel plate having front and rear surface extending between top and bottom ends and at least one leading blade located proximate to the bottom end of the mandrel plate. The apparatus further comprises at least one retainer plate pivotally supported from the mandrel plate between the bottom end of the mandrel plate and the leading blade, the at least one retainer plate being rotatable between an engaged position adapted to retain a plate barrier panel proximate to the front surface of the mandrel plate and a disengaged position.

The mandrel plate may include at least one support plate extending perpendicularly from the rear surface of the mandrel plate. Each of the at least one retainer plate may be pivotally supported from a corresponding at least one support plate. Each of the at least one retainer plate may include a slot adapted receive the corresponding at least one support plate therein. The at least one retainer plate may be pivotally supported by a pin extending through the corresponding at least one support plate to portions of the retainer plate to each side of the corresponding at least one support plate.

Each of the at least one retainer plate may extend between top and bottom surfaces. The top surfaces may be substantially planar. The top surfaces may include an upturned end lip. The end lip may include a retaining surface extending perpendicular to the top surface. The retaining surface may be located at a position adapted to correspond to the thickness of a barrier panel in the engaged position.

The bottom surfaces may be arcuate. The bottom surface may be cammed to displace the leading blade away from the mandrel plate as the at least one retainer plate is rotated from the engaged to the disengaged position.

Each of the at least one leading blade may be slidably supported by a corresponding one of the at least one support plate. Each of the at least one leading blade may be positioned below the mandrel plate.

Each of the at least one leading blade may have front and rear surfaces extending between top and bottom ends. The each of the front and rear surfaces may curve towards each other proximate to the bottom end to a tip of the at least one leading blade. The tip may be located midpoint of a thickness of the mandrel plate, retainer plate and leading blade. The tip may be located midpoint between the front and rear edges of the retainer plate when positioned at the engaged position. The top end may include an arcuate surface.

According to a further embodiment of the present invention there is disclosed a method of locating a barrier panel within a soil formation comprising locating a barrier panel against a front surface of a mandrel plate. The method further comprises displacing a leading blade from a position distal to the mandrel to a position adjacent to the mandrel so as to cause a retainer plate located between the mandrel plate and the leading blade to be rotated into an engaged position capturing a bottom edge of the barrier panel and pressing the mandrel plate and barrier panel into the soil formation.

Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention wherein similar characters of reference denote corresponding parts in each view,

FIG. 1 is a perspective view of an apparatus for locating a barrier panel within a soil formation according to a first embodiment of the present invention.

FIG. 2 is a detailed side view of the bottom of the apparatus of FIG. 1 at a first or run-in position.

FIG. 3 is a detailed side view of the bottom of the apparatus of FIG. 1 at a second or removal position.

FIG. 4 is an exploded view of the bottom of the apparatus of FIG. 1

DETAILED DESCRIPTION

Referring to FIG. 1, an apparatus for guiding a ground barrier panel into a soil formation according to a first embodiment of the invention is shown generally at 20. The apparatus 20 comprises a mandrel 22 extending between top and bottom edges, 24 and 26, respectively having a leading edge ground penetrating apparatus, generally indicated at 30 at the bottom edge 26. The apparatus is adapted to hold and guide the barrier panel 10 into the ground as will be more fully described below.

The barrier panel 10 comprises a body having a substantially rectangular outline defined by top 12, bottom 14 and first and second side edges, 16 and 18, respectively. As illustrated in FIG. 1, the barrier panel 10 may comprise a sheet of material having a variety of cross section profiles as are commonly known in the art. For example, by way of non-limited example, the barrier panel 10 may have a substantially planar, z-shaped, a double z-shape, u-shaped or c-shaped cross section profile. As illustrated in FIG. 1, the top and bottom edges 12 and 14 are substantially parallel to each other. Furthermore, the first and second side edges 16 and 18 are substantially parallel to each other and substantially perpendicular to the top and bottom edges. The barrier panel 10 may be formed of any known material in the art. Barrier members may be formed of metal, such as steel or aluminium, resins such as vinyl, polyvinyl chloride (PVC) or other known plastics, or composite materials such as fibreglass or carbon fibre by way of non-limiting example.

The mandrel 22 comprises a sheet of material having a cross section selected to correspond to the barrier panel 10 which it is intended to insert into the ground. In particular, the mandrel 22 may be formed of a sufficiently strong material to prevent bending or buckling during such insertion, such as, by way of non-limiting example, steel, stainless steel or the like.

With reference to FIGS. 2 and 3, the ground penetrating apparatus 30 comprises one or more leading blade 32 proximate to the bottom edge 26 of the mandrel 22 and a retainer plate 60 between the leading blade 32 and the mandrel 22. Although the operation of only a single ground penetrating apparatus 30 is illustrated in FIGS. 2 through 4, it will be appreciated the a plurality thereof may be located along the bottom edge 26 of the mandrel 22. As illustrated in FIG. 4, the mandrel includes a plurality of support plates 80 extending from a rear surface thereof. The support plates 80 extend to a bottom end 82 past the bottom edge 26 of the mandrel 22. The support plates 80 also include a bore 84 adapted to support the retainer plate 60 as will be more fully described below. A retaining block 86 extends perpendicularly from the support plate 80 proximate to the bottom end 82 thereof.

As illustrated in FIGS. 2 and 3, the leading blade 32 comprises an elongate body oriented parallel to the bottom edge 26 of the mandrel between top and bottom surfaces, 34 and 36, respectively. As illustrated in FIGS. 2 and 3, the leading blade 32 may be formed of front and rear plates, 38 and 40, respectively which are connected to each other by a bottom bridge 42 and a top bridge 44. The front plate 38 is substantially solid while the rear plate 40 includes slots 46 therein corresponding to support plates 80 extending from the mandrel 22 as will be more fully described below. To front and rear plates 38 and 40 form a void 41 therebetween adapted to receive the retainer block 86 as will be more fully described below. The top surface 34 has a concave profile with the rear edge raised and angled downwardly towards the front of the mandrel. As will be more fully set out below, the angle, generally indicated at 48 may be selected to be up to 45 degrees and serves to direct the retaining arm from a retracted position to an engaged position when inserted into a soil formation. The bottom surface 36 is rounded or tapered to a bottom most portion which is positioned to balance the forces acting upon the apparatus as the mandrel 22 is inserted into the soil.

The leading blade 32 is located below the bottom 26 of the mandrel 22 with the support plates 80 within the slots 46 and the retaining blocks 86 within the void 41 such that the leading blade 32 is permitted to move between a penetrating position as illustrated in FIG. 2 and a retracting position as illustrated in FIG. 3.

The retainer plate 60 comprises a body pivotally supported from the support plate 80 adapted to retain a bottom edge 14 of the barrier panel 10 against the mandrel. The retainer plate 60 is formed of an arm portion 62 with a distal lip portion 64. The arm portion 62 has a substantially planar top surface 66 and a bottom curved or arcuate surface 68, the purpose and shape of which will be more fully described below. As illustrated in FIG. 4, the retainer plate 60 includes a slot 70 extending from a rear edge therethrough sized to receive the support plate 80 therebetween and a bore 72 located proximate to rear of the retainer plate. When positioned with the support plate 80 within the slot 70, and the bores 84 and 72 aligned a pin may be passed therethrough to pivotally secure the retainer plate 60 to the mandrel.

With reference to FIG. 3, when the apparatus is inserted into the soil, the angled rear edge of the top surface 34 of the leading blade is pressed upward by the soil due to the downward movement of the apparatus. The rear surface acts upon the bottom surface of the leading blade 32 so as to cam it forward thereby rotating the retainer plate 60 upwards to the retaining position as illustrated In FIG. 2. In the retaining position shown in FIG. 2, the lip portion 64 has been positioned to capture the bottom edge of a barrier panel by the upward movement of the leading blade 32. Continued downward pressure due to the movement of the apparatus will retain the retaining plate 60 in the retaining position. As illustrated in FIG. 2, the front plate 38 of the leading blade is substantially in line with the mandrel 22 with the arm portion 62 of the retaining arm therebetween. Similarly, the rear plate 40 is positioned below a support block 88 on the mandrel 22 with the arm portion therebetween. Thereby all forces applied to the leading blade 32 will be transmitted through the arm portion to the mandrel 22 limiting any stress on the leading blade.

When the barrier panel has been inserted into the ground to a sufficient depth, the mandrel may be pulled upward, thereby unloading upward pressure on the leading blade 32. The pulling of the mandrel in an upward direction will pull the allow the leading blade 32 to be pulled away from the mandrel 22, thereby also permitting the retaining plate to rotate downward to the position illustrated in FIG. 3, whereby the apparatus will release the barrier panel.

As illustrated in FIG. 2, the bottom surface 36 of the leading blade 32 includes a lowermost portion from which the leading surface curves away from both to the front and the rear. The position of the lowermost portion is selected such that the distance therefrom to the front and rear edges of the retaining arm, generally indicated at 102 and 104 respectively are substantially equal. In such a manner, any lateral forces applied to the apparatus during insertion into the soil will be substantially balanced preventing misalignment of the barrier panels.

While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims. 

What is claimed is:
 1. An apparatus for locating a barrier panel within a soil formation comprising: a mandrel plate having front and rear surface extending between top and bottom ends; at least one leading blade located proximate to said bottom end of the mandrel plate; and at least one retainer plate pivotally supported from said mandrel plate between the bottom end of the mandrel plate and said leading blade, said at least one retainer plate being rotatable between an engaged position adapted to retain a plate barrier panel proximate to said front surface of said mandrel plate and a disengaged position.
 2. The apparatus of claim 1 wherein said mandrel plate includes at least one support plate extending perpendicularly from said rear surface of said mandrel plate.
 3. The apparatus of claim 2 wherein each of said at least one retainer plate is pivotally supported from a corresponding at least one support plate.
 4. The apparatus of claim 3 wherein each of said at least one retainer plate includes a slot adapted receive said corresponding at least one support plate therein.
 5. The apparatus of claim 4 wherein said at least one retainer plate is pivotally supported by a pin extending through said corresponding at least one support plate to portions of said retainer plate to each side of said corresponding at least one support plate.
 6. The apparatus of claim 1 wherein each of said at least one retainer plate extending between top and bottom surfaces.
 7. The apparatus of claim 6 wherein said top surfaces are substantially planar.
 8. The apparatus of claim 7 wherein said top surfaces include an upturned end lip.
 9. The apparatus of claim 8 wherein said end lip includes a retaining surface extending perpendicular to said top surface.
 10. The apparatus of claim 9 wherein said retaining surface is located at a position adapted to correspond to the thickness of a barrier panel in said engaged position.
 11. The apparatus of claim 6 wherein said bottom surfaces are arcuate.
 12. The apparatus of claim 11 wherein said bottom surface is cammed to displace said leading blade away from said mandrel plate as said at least one retainer plate is rotated from said engaged to said disengaged position.
 13. The apparatus of claim 2 wherein each of said at least one leading blade is slidably supported by a corresponding one of said at least one support plate.
 14. The apparatus of claim 13 wherein each of said at least one leading blade is positioned below said mandrel plate.
 15. The apparatus of claim 13 wherein each of said at least one leading blade has front and rear surfaces extending between top and bottom ends.
 16. The apparatus of claim 15 wherein said each of said front and rear surfaces curve towards each other proximate to said bottom end to a tip of said at least one leading blade.
 17. The apparatus of claim 16 wherein said tip is located midpoint of a thickness of said mandrel plate, retainer plate and leading blade.
 18. The apparatus of claim 16 wherein said tip is located midpoint between said front and rear edges of said retainer plate when positioned at said engaged position.
 19. The apparatus of claim 15 wherein said top end includes an arcuate surface.
 20. A method of locating a barrier panel within a soil formation comprising: locating a barrier panel against a front surface of a mandrel plate; displacing a leading blade from a position distal to the mandrel to a position adjacent to the mandrel so as to cause a retainer plate located between the mandrel plate and the leading blade to be rotated into an engaged position capturing a bottom edge of the barrier panel; and pressing said mandrel plate and barrier panel into the soil formation. 